When I came to, I found myself in an unfamiliar room.

I was taking advantage of my summer break to go on a ten day vacation with my best friend. We were enjoying the sights of Okinawa on the bus from the airport when—

And that’s the last thing I remember.

Is this the hotel? Did I fall asleep on the bus…?

The door wouldn’t open and what we thought were windows were actually just screens displaying images of the outside. When we searched the room for some clue as to where we were, we found yet another screen displaying a single, mercilessly cold sentence:

“You have been selected to participate in a behavioral analysis experiment.”

We have to choose and complete a task presented on the screen as instructed if we ever want to see the light of day again.

If we play our cards right, we can get out in ten days—ten choices.

Our options are extremely limited—

Either my best friend has to physically harm me,
or I have to debase my best friend sexually.

At the mercy of these inhumanly cruel choices, the two of us decide to—

This summer vacation begins with a car accident…

Our protagonist protects a man from an out of control car, but gets hit and loses his memory in the process. The man he saved happens to be the owner of a jazz bar, sótano. Out of sympathy for his hapless savior, the man decides to set him up with a job and a place to live.

From the outside, sótano looks like a cozy little jazz bar, but behind the scenes they solve problems that the police and legitimate detective agencies won’t touch. The staff there give our protagonist the name “Haru”. He gradually makes his way deeper into the organization, and the hearts and lives of the staff, while working as an apprentice bartender. But just who is Haru really…?